Phase separated signals are used in a variety of situations. Clock and data recovery (CDR) mechanisms, for example, utilize an edge clock and a data clock phase separated by 90°, and corresponding complements. The edge clocks may be used to take edge samples, and the data clocks may be used to take data samples. A CDR control loop may use the samples to adjust edges of the clock signals to align the edge clocks with data transitions so that the data clocks are nominally in the centers of the data eyes. Errors in the 90° phase separation between the edge clock and the data clock may result in reduced margin.
Conventional techniques to correct errors in 90° phase separation, referred to herein as quadrature phase correction, are based on assumptions that introduce errors or use relatively complex finite state machines and sensitive analog circuits, which may be inefficient in terms of area and power consumption, and which may be relatively difficult to debug.
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